Disposable quarded finger scalpel for inserting a line in a patent and lock off therefor

ABSTRACT

A guarded finger scalpel is squeezed between the thumb and forefinger to advance a blade out of an opening. The blade is used to make an incision in the patient&#39;s skin, thereby facilitating insertion of a catheter and its line in a patient. Thereafter, the manual pressure is released, and the blade is automatically retracted. This prevents inadvertent or accidental nicks or cuts and hence eliminates or, at least, substantially reduces the exposure to the AIDS virus or other infectious diseases. A lock-off means is employed, subsequent to the surgical procedure, to prevent further blade exposure during clean-up and disposal.

CROSS-REFERENCE TO RELATED APPLICATION

The present invention constitutes a continuation-in-part of applicationSer. No. 08/079,985 filed Jun. 18, 1993, now U.S. Pat. No. 5,370,654,the disclosure of which is incorporated herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to a finger scalpel for making a small cutor incision in a patient's skin to facilitate insertion of a catheter,and more particularly, to a guarded finger scalpel to preventinadvertent or accidental nicks or cuts incurred by any of the healthcare providers involved in using the finger scalpel or in the subsequentclean up and disposal thereof.

BACKGROUND OF THE INVENTION

In the process of establishing a line in a patient (as for example,during a heart bypass operation) a catheter is inserted into thepatient. The purpose of the catheter may be to position a sensor orother device within the patient or to inject a medication or a dye intothe patient. In order to insert the catheter, it is first necessary toinsert a guide wire through the patient's skin and to locate one of thepatient's veins (or other vessel, body cavity or organ). The guide wirecomprises a flexible cable which is inserted through a puncture in thepatient's skin, the puncture being made by a needle. Since the punctureis relatively small compared to the catheter, and since the catheter isrelatively soft and flexible and may bend, it is necessary to enlargethe puncture by making a small incision or cut substantially at thepuncture or adjacent thereto.

This relatively small cut is made by a finger scalpel. The fingerscalpel comprises a surgical blade attached to a small plastic handlethat is grasped, typically, between the surgeon's thumb and forefinger.

After the cut is made, the surgeon merely drops the finger scalpel onthe tray or on the patient's gurney. Since the blade is exposed (andusually contains blood or bodily fluids) this is a hazardous situation.The danger occurs in using the finger scalpel, or in cleaning up theoperating room or patient's room, or in subsequent disposal of the usedscalpel.

Accidental or inadvertent contact with the unguarded finger scalpeloften results in the health care provider being nicked or cut, andexposure with the blood or bodily fluids on the blade may result in thehealth care provider sero-converting and thus becoming infected withHepatitis B or the deadly HIV ("AIDS") virus.

Even if an infection does not occur, repeated testing and observation isnecessary whenever a known AIDS patient is involved. This testing isworrisome, inconvenient and costly.

Conversely, there is also a risk to the patient in the event the surgeonor other health care provider is infected with AIDS or any contagiousdisease.

While no specific data is available with regard to finger scalpels, therisk is at least comparable to the problems associated with needlesticks. A study was made by the Needle Stick Surveillance Group of theC.D.C. (Centers for Disease Control). Out of 3,978 needle sticks frompatients known to be HIV positive, 13 health care workers becameinfected--roughly 1 out of 300. Thus, from a single needle stick whiletreating an AIDS patient in an operating room or other environment, thechances are roughly 1 out of 300 that the surgeon, nurse or otherindividual health care provider will sero-convert and become HIVpositive.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide aguarded finger scalpel which substantially eliminates inadvertent oraccidental contact with the blade, thereby preventing the spread ofinfectious diseases.

It is another object of the present invention to provide a guardedfinger scalpel having a retracted blade; such that when the scalpel isgrasped or squeezed between the surgeon's thumb and forefinger, theblade is advanced and exposed for use; and such that when the scalpel isreleased, the blade is automatically retracted to its original positionand is thereby guarded against accidental or inadvertent contact.

It is a further object of the present invention to provide a lock-offmeans to prevent movement of the blade relative to the guard followinguse of the guarded finger scalpel during a surgical procedure, therebypreventing accidental nicks or cuts during clean-up.

In accordance with the teachings of the present invention, the guardedfinger scalpel includes a body normally grasped between a surgeon'sthumb and forefinger. This body includes a blade guide means having aforward portion provided with an opening formed therein. A blade isslidably guided within the blade guide means and has respective sides. Apair of spring arms are connected to the blade and extend laterally ofthe blade on respective sides thereof. These spring arms are manuallysqueezed towards each other, thereby advancing the blade outwardlythrough the opening in the forward portion of the blade guide means inthe body. Conversely, the blade is automatically retracted within thebody when the spring arms are released to return to their originalposition.

In one embodiment, the body comprises a substantially rectangular framehaving top and bottom walls and side portions provided with respectiveopenings formed therein; the spring arms extend laterally through theopenings, respectively, and are confined by the top and bottom walls ofthe frame.

In another embodiment, the body is substantially resilient and hasrespective side walls, and the respective spring arms are confinedwithin the resilient body and engage the respective side walls thereof.With this arrangement, the respective side walls of the resilient bodymay be squeezed together to thereby deflect the spring arms towards eachother.

Viewed in another aspect, the present invention constitutes animprovement in the method of inserting a line in a patient, wherein aneedle is used to make a puncture in the patient's skin to locate a vein(or other vessel, cavity or organ) in the patient. A guide wire isinserted through the needle and through the puncture and into thepatient, and the needle is removed. A catheter is inserted over theguide wire and into the patient, the wire being removed when thecatheter is installed. The improvement includes the steps of providing aguarded finger scalpel having a covered blade, manually grasping theguarded finger scalpel and advancing the blade, making a cut in thepatient's skin substantially at the puncture before the catheter isinserted over the guide wire, thereby facilitating insertion of thecatheter, and automatically retracting the blade within the guardedfinger scalpel, thereby preventing nicks or cuts due to accidental orinadvertent contact with the scalpel during use, clean-up or disposalthereof.

Viewed in still another aspect, the present invention provides a fingerscalpel for use by a surgeon in installing a line in a patient in ahospital, wherein the finger scalpel is part of a disposable kit, andwherein the finger scalpel includes a body normally intended to begrasped between the surgeon's thumb and forefinger, the body having ablade mounted thereon. In accordance with the teachings of the presentinvention, a guard is provided on the body. The guard has a normalposition covering the blade and preventing accidental contact therewith.A resilient means maintains the guard in the normal position thereof,such that the resilient means may be manually opposed as the fingerscalpel is grasped by the surgeon, thereby exposing the blade relativeto the guard. A lock-off means independent of the resilient means isprovided. The lock-off means is operative in the normal position of theguard and prevents blade exposure, such that the clean-up personnel inthe hospital are protected against nicks or cuts during disposal of thekit.

In a preferred embodiment, the lock-off means includes a lock-off buttoncarried transversely by one of the side walls of the frame.

The inner member within the frame has a pocket formed therein. Thelock-off button may be pushed inwardly of the frame and received withinthe pocket in the inner member, thereby locking the inner member to theframe and preventing relative sliding movement therebetween.

In another embodiment, the lock-off button is carried on a depressibletang formed on the one side wall of the frame.

These and other objects of the present invention will become apparentfrom a reading of the following specification taken in conjunction withthe enclosed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the guarded fingerscalpel of the present invention.

FIG. 2 is a cross-sectional view thereof, taken along the lines 2--2 ofFIG. 1, and showing the respective spring arms connected to the blade,and further showing the spring arms extending through respectiveopenings formed in the side portions of the rectangular frame.

FIG. 3 is a cross-sectional view thereof, taken along the lines 3--3 ofFIG. 2, showing the blade within the blade guide means.

FIG. 4 is a pictorial view showing the guarded finger scalpel beinggrasped by the surgeon.

FIG. 5 is a further pictorial view, corresponding substantially to FIG.4, but showing the respective spring arms of the guarded finger scalpelbeing squeezed between the surgeon's thumb and forefinger to advance theblade out of the blade guide means.

FIG. 6 is an exploded perspective view, showing the assembly of thecomponents of the guarded finger scalpel of FIG. 1.

FIG. 7 is a side elevation of a second embodiment of the guarded fingerscalpel of the present invention with certain parts thereof broken awayand sectioned to show the blade fully retracted within the body of theguarded finger scalpel.

FIG. 8 corresponds substantially to FIG. 7, but shows the resilient bodyof the guarded finger scalpel being squeezed between the surgeon's thumband forefinger to advance the blade through an opening in the body ofthe guarded finger scalpel.

FIG. 9 is a top plan view corresponding to FIG. 7, with certain partsbroken away, and showing a pair of spring arms connected betweenrespective side portions of the blade and the resilient body of theguarded finger scalpel.

FIG. 10 is a further top plan view with certain parts broken away andsectioned, corresponding substantially to FIG. 9, but showing the bodysqueezed to deflect the spring arms to extend the blade.

FIGS. 11--21 are pictorial views showing the sequence of using theguarded finger scalpel to make a cut (or cuts) in the patient to enablea catheter to be inserted into the patient.

FIG. 11 shows the needle making a puncture in the patient's skin tolocate a vein, and further shows (in exploded relationship thereto) aflexible guide wire about to be inserted into the needle.

FIG. 12 shows the guide wire inserted into the vein, and further showsthe needle being withdrawn therefrom.

FIG. 13 is a cross-sectional view thereof, taken along the lines 13--13of FIG. 12, and drawn to an enlarged scale.

FIG. 14 shows the scalpel being picked up by the surgeon.

FIG. 15 shows the resilient body of the scalpel being squeezed betweenthe surgeon's thumb and forefinger to thereby advance the blade out ofthe body of the guarded finger scalpel.

FIG. 16 shows the blade being used to make a small cut (or cuts) at thepuncture in the patient's skin or substantially adjacent thereto,thereby enlarging the puncture to facilitate insertion of the catheter.

FIG. 17 shows the guarded finger scalpel being released to automaticallyretract the blade.

FIG. 18 shows the catheter being inserted over the guide wire,concentrically thereof.

FIG. 19 shows the catheter being inserted through the cut and into thepatient's vein.

FIG. 20 is a cross-sectional view thereof, taken along the lines 20--20of FIG. 19, and drawn to an enlarged scale.

FIG. 21 is a further cross-sectional view, corresponding substantiallyto FIG. 20, but showing the guide wire being withdrawn from the catheterin the patient's vein.

FIG. 22 is a schematic block diagram showing the preferred method ofusing the guarded finger scalpel of the present invention.

FIG. 23 is a perspective view of a further embodiment of the presentinvention, wherein a lock-off means is provided to lock the blade in itsretracted position and prevent further movement of the blade relative tothe guard on the frame.

FIG. 24 is a portion of FIG. 23, drawn to an enlarged scale, and showinga lock-off button on the frame.

FIG. 25 is a cross-sectional view thereof, taken along the lines 25--25of FIG. 24 and drawn to an enlarged scale, and showing the pocket formedwithin the inner member.

FIG. 26 is a further cross-sectional view, corresponding substantiallyto FIG. 25, but showing the lock-off button pushed inwardly and receivedwithin the pocket formed in the inner member, thereby locking the innermember and hence the blade in its retracted position.

FIG. 27 is a longitudinal sectional view, taken along the lines 27--27of FIG. 23 and drawn to an enlarged scale, and showing the inner memberbeing retracted into its normal position on the frame.

FIG. 28 is a further longitudinal sectional view, correspondingsubstantially to FIG. 27, but showing the inner member fully retractedwithin the frame and the lock-off button pushed inwardly and receivedwithin the pocket on the inner member, thereby locking the inner memberto the frame and preventing further movement of the inner memberrelative to the frame.

FIG. 29 is a perspective view of a further embodiment, whereby thelock-off button is carried by a depressible tang formed on a side wallof the frame.

FIG. 30 is an enlarged portion of FIG. 29, showing the lock-off buttonon the disposable tang being pushed inwardly of the frame and into thelocking position thereof.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1-3, the guarded finger scalpel 10 of thepresent invention includes a substantially rectangular frame 11 having atop wall 12, a bottom wall 13 and respective side portions 14 and 15having openings 16 and 17, respectively, formed therein. A pair ofspring arms 18 and 19 (resilient means), respectively, are confinedbetween the top wall 12 and the bottom wall 13 of the frame 11, beingdisposed rearwardly of the frame 11 as shown in FIG. 3, and extendlaterally thereof through the openings 16 and 17, respectively.

These spring arms 18 and 19 are bifurcated and, preferably, are formedfrom a single plastic moldment (as shown more clearly in FIG. 2) and arejoined together, first, at a forward portion 20 and, second, at arearward cap 21. The forward portion 20 of the spring arms 18, 19includes a longitudinally-extending lug 22 received within alongitudinal slotted opening 23 formed within a surgical blade 24. Thelug 22 may be swaged over the blade 24 and secured thereto (as shownmore clearly in FIGS. 2 and 3) by hot-staking or other productionprocess.

The blade 24 is slidably guided within a blade guide means 25 having anopening 26. The blade guide means 25 constitutes a guard for the blade24 and (in this embodiment) is substantially rectangular and is formedintegrally with the frame 11, as for example, by a unitary plasticmoldment. Preferably, the blade guide means 25 is transparent, so thatthe blade 24 is visible at all times (even when the blade 24 is normallyconfined therein).

The exposed faces of the laterally-extending spring arms are roughened,as at 27 in FIG. 1, to facilitate a manual grasping and manipulation ofthe guarded finger scalpel 10.

When the guarded finger scalpel 10 is thus grasped between the surgeon'sthumb and forefinger (FIG. 4), the spring arms 18, 19 are squeezedtogether (FIG. 5) laterally inwardly of the frame 11 to thereby advancethe blade 24 out of the opening 26.

Thus the blade 24 of the guarded finger scalpel 10 of the presentinvention is only exposed while a cut or cuts are being made, therebysubstantially reducing (if not eliminating altogether) the risksassociated with using a conventional unguarded finger scalpel, not onlyin the highly-stressed environment of an operating room or critical careunit, but also in the subsequent clean up and disposal of the overallkit including the scalpel.

With reference again to FIG. 2, and with further reference to FIG. 6,the blade 24 and the spring arms 18 and 19 with their rearward cap 21constitutes a subassembly 28 or inner member nested within the frame 11.In the assembly of the guarded finger scalpel 10, the subassembly 28 isreceived through an opening 29 in a rear wall 30 of the frame 11. Thespring arms 18 and 19 are squeezed together to clear the opening 30, andthe spring arms 18, 19 are then released to enable the spring arms 18,19 through the openings 16, 17 and laterally of the frame 11. The cap 21is then seated against the rear wall 30 of the frame 11 and may besecured thereby by protrusions (not shown) or by ultrasonic welding,hot-staking or any suitable production process.

The guarded finger scalpel 10 comprises only three parts: the moldedframe 11, the molded spring arms 18 and 19, and the metal blade 24,respectively. Accordingly, the guarded finger scalpel 10 facilitateshigh-volume low-cost automated manufacture.

An alternate embodiment 10' of the guarded finger scalpel of the presentinvention is illustrated in FIGS. 7-10. This guarded finger scalpel 10'has a resilient body 31, preferably of a suitable molded plasticmaterial, and being relatively small and easy to handle and to orient.Preferably, the body 31 has complementary halves 32 and 33,respectively, joined together along a common longitudinal midplane 34and suitably secured together, as for example, by ultrasonic welding.

A blade guide means or frame 35 is mounted within the resilient body 31,and a blade 36 is slidably guided within the frame 35. The blade 36 hasrespective sides 37 and 38; and a pair of spring arms 39 and 40,respectively, are connected between the sides 37, 38 and the resilientbody 31.

As the resilient body 31 is squeezed between the surgeon's thumb andforefinger, as shown in FIGS. 8 and 10, the respective spring arms 39and 40 deflect, that is, are compressed towards the frame 35; and as aresult, the blade 36 is advanced forwardly out of an opening 41 formedin the body 31.

Conversely, when the finger pressure is released, the respective springarms 39 and 40 return to their original position (FIGS. 7 and 9) and theblade 36 is again retracted within the body 31.

The sides of the resilient body are indented, as at 42, to facilitatemanual manipulation of the guarded finger scalpel 10'.

Thus, with the guarded finger scalpels 10 and 10' of the presentinvention, the blades 24 and 36, respectively, are exposed only whenmaking a cut or cuts in the patient's skin. Otherwise, the blades 24, 36are covered at all times. Accordingly, the guarded finger scalpels 10and 10' of the present invention protect against inadvertent oraccidental nicks or cuts occasionally encountered by health careproviders (such as surgeons, nurses, technicians, operating roomassistants and clean-up personnel) and the serious health risksassociated therewith.

The protection also extends to the patient (or patients) if the surgeonor other health care provider is infected with HIV (the deadly AIDSvirus) or any other contagious disease. In the event an unguarded fingerscalpel becomes contaminated by tainted blood from the surgeon or otherhealth care provider, the disease may be inadvertently communicated tothe patient.

The protection afforded by the guarded finger scalpels 10 and 10' of thepresent invention, and the benefits and advantages of its improvedmethod, are illustrated in FIGS. 11-21.

In FIG. 11, a needle 100 is used to make a puncture 101 in a patient'sarm 102 to thereby locate a vein (for example). The needle 100 is an"introducer" needle. In some cases, it may be necessary to first use asmaller "starter" needle (now shown) to locate the patient's vein.Thereafter, a flexible guide wire 103 is inserted through the needle 100and through the puncture 101 (FIG. 12) and into the vein 104 (FIG. 13).The needle 100 is then removed and the guide wire 103 remains in thelumen, that is, within the opening in the vein, artery or intestine ofthe patient.

The guarded finger scalpel 10 (or 10') of the present invention isgrasped by the surgeon, usually between the surgeon's thumb andforefinger (FIG. 14), and is squeezed to advance the blade 24 (FIG. 15).The blade 24 is then used to make an incision or cut 105 in thepatient's skin (FIG. 16). One or more cuts 105 may be made, therebyenlarging the puncture 101 (and facilitating the subsequent insertion ofa catheter). Manual pressure is released to retract the blade 24, andthe guarded finger scalpel 10 is lifted away from the cut 105.

The blade 24 is no longer exposed, and the guarded finger scalpel 10 isthen discarded.

Thereafter, a catheter 106 (FIG. 18) is slipped over the guide wire 103and through the cut 105 (FIG. 19) and into the patient's vein 104 (FIG.20). Once the catheter 106 is in place, or while the catheter 106 isbeing inserted, the guide wire 103 is removed (as shown in FIG. 21).

This sequence of steps of the preferred method of using the guardedfinger scalpels 10 and 10' of the present invention is illustrated inthe schematic block diagram of FIG. 22.

With reference to FIGS. 23-28, the guarded finger scalpel 10 is providedwith a lock-off means 200. In this embodiment, the lock-off means 200includes a lock-off button 201 carried by a side portion or wall 14 ofthe guarded finger scalpel 10. This lock-off button 201, as shown moreclearly in FIG. 25, includes an enlarged head 202, a tapered body 203,and an enlarged foot 204, all of which, if desired, may be molded from asuitable plastic material. The lock-off button 201 may be pushed througha hole 205 in the side wall 14 and loosely retained therein between theenlarged head 202 and the enlarged foot 204. The enlarged head 202 maybe roughened or knurled, as at 206 in FIG. 24, to facilitate aconvenient manipulation thereof.

The forward portion 20 of the inner member (comprising the respectivespring arms 18 and 19) has a blind pocket 207 formed therein. This blindpocket 207 is preferably tapered inwardly thereof and has an internalannular shelf 208 formed therein, as shown more clearly in FIG. 25.

When the surgical procedure of installing a line in a patient has beencompleted, and no further use of the guarded finger scalpel 10 isrequired, the lock-off button 201 may be pushed inwardly thereof (FIG.24) so that its enlarged foot 204 is "popped" into the blind pocket 207and is received firmly therein, as shown more clearly in FIG. 26. Theforward portion 20 of the inner member is thereby locked to the frame11.

Thereafter, the blade 24 cannot extend beyond the guard 25 even if therespective spring arms 19 and 20 (or one of them) is squeezedinadvertently or accidentally. This feature is very desirable inpreventing nicks or cuts to the surgeon, nurse, technician or clean-uppersonnel while disposing of the guarded finger scalpel 10 and itsoverall kit. Thus, the guarded finger scalpel 10 of the presentinvention is provided, not only with a guard for protection whileinstalling a line, trocar or similar medical device in a patient, but isalso provided with the lock-off means 200 for protection during disposaland clean-up.

With reference to FIGS. 29 and 30, a lock-off button 209 may be moldedintegrally with a depressible tang 210 formed by a pair of parallelslots 211 and 212, respectively, in the side wall 14 of the guardedfinger scalpel 10.

Obviously, many modifications may be made without departing from thebasic spirit of the present invention. For example, instead of thepatient's vein (as shown herein) the flexible guide wire 103 may beinserted into a patient's organ, vessel or body cavity under certaincircumstances during a surgical procedure. Also, the guarded fingerscalpel may be used by any health care provider, such as a cardiologist,pulmonary doctor, anesthesiologist, nurse, etc. Accordingly, it will beappreciated by those skilled in the art that within the scope of theappended claims, the invention may be practiced other than has beenspecifically described herein.

What is claimed is:
 1. A disposable guarded finger scalpel, wherein thedisposable guarded finger scalpel is used while inserting a line in apatient, comprising a frame normally grasped between a thumb andforefinger, the frame including a blade guard forwardly thereof andhaving an opening therein, an inner member nested within the frame andincluding at least one spring arm disposed rearwardly of the frame andextending laterally therefrom, the inner member including a forwardportion having a longitudinal lug formed thereon, a blade having alongitudinal slot receiving the lug on the forward portion of the innermember, thereby mounting the blade on the inner member, the bladenormally being retracted within the blade guard, the inner member havinga cap means rearwardly thereof, and the frame having a rear end wallabutting against the cap means on the inner member, thereby securing theinner member within the frame, wherein the at least one spring arm ismanually squeezed laterally inwardly of the frame, thereby advancing theblade outwardly through the opening in the blade guard and therebyautomatically retracting the blade within the guard when the at leastone spring arm is manually released, and means for locking the blade ina retracted position of the blade on the frame.
 2. The disposableguarded finger scalpel of claim 1, wherein the frame is substantiallyrectangular, the frame having top and bottom walls, the frame furtherhaving side portions with respective openings formed therein, andwherein the at least one spring arm of the inner member comprises a pairof spring arms extending laterally through the openings, respectively,and confined by the top and bottom walls of the frame.
 3. The disposableguarded finger scalpel of claim 2, wherein the blade guard istransparent, such that the blade is visible within the guard.
 4. Thedisposable guarded finger scalpel of claim 2, wherein the spring armsare grasped between the thumb and forefinger, and wherein the springarms have side walls provided with respective roughened portions toaccommodate the thumb and forefinger, respectively.
 5. A disposableguarded finger scalpel, comprising a generally rectangular frame havingtop and bottom walls and respective side walls, each of the side wallsbeing provided with an opening formed therein, the frame having atransparent forward portion providing a blade guard, a blade slidablyguided within the guard, the blade having a respective side portionprovided with a longitudinally-extending slot, an inner member receivedwithin the frame and including a forward portion provided with alongitudinal rib received within the longitudinally-extending slot onthe blade, and the inner member including a pair of spring arms formedintegrally with the forward portion of the inner member and extendingthrough the respective openings in the side walls of the frame laterallythereof, the spring arms being disposed rearwardly on the frame, and theframe having a rear end wall means cooperating with a cap means on thespring arms, thereby longitudinally securing the spring arms within theframe, such that the spring arms may be squeezed laterally together andinwardly of the frame, thereby advancing the blade forwardly of thetransparent blade guard, and such that when the spring arms arereleased, the blade is automatically retracted within the transparentguard, and means for locking the blade in a retracted position of theblade on the frame.
 6. In the method of inserting a line in a patient,wherein a needle is used to make a puncture in the patient's skin, suchthat a guide wire may be inserted through the needle and the punctureand into the patient, the needle being removed, and such that a cathetermay be inserted subsequently over the guide wire and into the patient,the wire being removed when the catheter is installed, the improvementcomprising the steps of providing a disposable guarded finger scalpelincluding a frame having a transparent blade guard forwardly thereof andhaving a rearward portion, an inner member nested within the frame andincluding at least one spring arm disposed rearwardly of the frame andextending laterally therefrom, the inner member including a forwardportion having a blade mounted thereon, the blade normally beingretracted within the guard, the inner member further including a capmeans rearwardly thereof, and the frame having a rear end wall abuttingagainst the cap means on the inner member, thereby securing the innermember within the frame, manually grasping the rearward portion of theframe of the disposable guarded finger scalpel, viewing the blade withinthe transparent guard, and depressing the at least one spring armlaterally inwardly of the frame, thereby advancing the blade out of theguard, making a cut in the patient's skin substantially at the puncturebefore the catheter is inserted over the guide wire, therebyfacilitating insertion of the catheter, and releasing the at least onespring arm laterally outwardly of the frame, thereby automaticallyretracting the blade within the transparent guard of the disposableguarded finger scalpel, further including the step of providing alock-off means on the frame and moving the lock-off means into a lockedposition to preclude movement of the blade relative to the guard.
 7. Adisposable kit for installing a line in a patient, the kit including aneedle for making a puncture in the patient's skin and further includinga catheter and a guide wire therefor, and a guarded finger scalpel inthe kit, the guarded finger scalpel comprising an outer frame, an innermember nested within the frame, slidably guided therein for longitudinalmovement relative to the frame, and including at least oneintegrally-formed spring arm extending laterally therefrom, the innermember further including a forwardly-extending portion having alongitudinal lug formed thereon, a blade having a longitudinal slotreceiving the lug on the forwardly-extending portion of the innermember, thereby mounting the blade thereon, the frame having a rear endwall, and the inner member having a cap means secured to the rear endwall of the frame, thereby confining the inner member within the frame,and a guard on the frame forwardly thereof and substantially enclosingthe blade, such that when the spring arm is squeezed between the thumband forefinger, the spring arm is depressed into the frame, therebyextending the inner member forwardly of the frame so that the bladeextends beyond the guard on the frame, such that the blade on theguarded finger scalpel may be used to enlarge the puncture in thepatient's skin, thereby facilitating insertion of the catheter into thepatient, and such that upon release of the thumb and forefinger, thespring arm extends laterally of the frame and the blade is retractedwithin the guard on the frame, thereby protecting the respective healthcare providers in installing the line in the patient and in cleaning upand subsequent disposal of the kit including the guarded finger scalpeltherein, and further including means for locking the blade in aretracted position of the blade.
 8. In a finger scalpel for use by asurgeon in installing a line in a patient in a hospital, wherein thefinger scalpel is part of a disposable kit, and wherein the fingerscalpel includes a body normally intended to be grasped between thesurgeon's thumb and forefinger, the body having a blade mounted thereon,the improvement comprising a guard on the body, the guard having anormal position covering the blade and preventing accidental contacttherewith, resilient means maintaining the guard in the normal positionthereof, such that the resilient means may be manually opposed as thefinger scalpel is grasped by the surgeon, thereby exposing the bladerelative to the guard, and lock-off means independent of the resilientmeans, operative in the normal position of the guard and preventingblade exposure, such that the clean-up personnel in the hospital areprotected against nicks or cuts during disposal of the kit.
 9. Theimprovement of claim 8, wherein the body comprises a frame including apair of side walls having respective openings therein, wherein an innermember is confined within the frame and is guided for slidable movementtherein, the inner member carrying the blade thereon, and wherein theresilient means comprises a pair of spring arms carried by the innermember, each spring arm extending laterally through a respective openingin the side walls of the frame.
 10. In a finger scalpel for use by asurgeon in installing a line in a patient in a hospital, wherein thefinger scalpel is part of a disposable kit, and wherein the fingerscalpel includes a body normally intended to be grasped between thesurgeon's thumb and forefinger, the body having a blade mounted thereon,the improvement comprising a guard on the body, the guard having anormal position covering the blade and preventing accidental contacttherewith, resilient means maintaining the guard in the normal positionthereof, such that the resilient means may be manually opposed as thefinger scalpel is grasped by the surgeon, thereby exposing the bladerelative to the guard, and lock-off means independent of the resilientmeans, operative in the normal position of the guard and preventingblade exposure, such that the clean-up personnel in the hospital areprotected against nicks or cuts during disposal of the kit, wherein thebody comprises a frame including a pair of side walls having respectiveopenings therein, wherein an inner member is confined within the frameand is guided for slidable movement therein, the inner member carryingthe blade thereon, and wherein the resilient means comprises a pair ofspring arms carried by the inner member, each spring arm extendinglaterally through a respective opening in the side walls of the frame,wherein the lock-off means comprises a lock-off button carriedtransversely by one of the side walls of the frame, and the inner memberwithin the frame having a pocket formed therein, such that the lock-offbutton may be pushed inwardly of the frame and received within thepocket in the inner member, thereby locking the inner member to theframe and preventing relative sliding movement therebetween.
 11. Theimprovement of claim 10, wherein the lock-off button is carried on adepressible tang formed on the one side wall of the frame.
 12. In themethod of inserting a line in a patient, wherein a needle is used tomake a puncture in the patient's skin, such that a guide wire may beinserted through the needle and the puncture and into the patient, theneedle being removed, and such that a catheter may be insertedsubsequently over the guide wire and into the patient, the wire beingremoved when the catheter is installed, the improvement comprising thesteps of providing a disposable guarded finger scalpel including a framehaving a blade guard forwardly thereof and having a rearward portion, aninner member nested within the frame and including at least one springarm disposed rearwardly of the frame and extending laterally therefrom,the inner member including a forward portion having a blade mountedthereon, the blade normally being retracted within the guard, providinga lock-off means, manually grasping the rearward portion of the frame ofthe disposable guarded finger scalpel, depressing the at least onespring arm laterally inwardly of the frame, thereby advancing the bladeout of the guard, making a cut in the patient's skin substantially atthe puncture before the catheter is inserted over the guide wire,thereby facilitating insertion of the catheter, releasing the at leastone spring arm laterally outwardly of the frame, thereby automaticallyretracting the blade within the guard of the disposable guarded fingerscalpel, and moving the lock-off means into a locked position to preventmovement of the blade relative to the guard.
 13. A disposable kit forinstalling a line in a patient, the kit including a needle for making apuncture in the patient's skin and further including a catheter and aguide wire therefor, and a guarded finger scalpel in the kit, theguarded finger scalpel comprising an outer frame, an inner member nestedwithin the frame, slidably guided therein for longitudinal movementrelative to the frame, and including at least one integrally-formedspring arm extending laterally therefrom, the inner member furtherincluding a forwardly-extending portion having a lug extending forwardlythereof, a blade having a longitudinal slot receiving the lug on theforwardly-extending portion of the inner member, thereby mounting theblade thereon, a guard on the frame forwardly thereof and substantiallyenclosing the blade, such that when the spring arm is squeezed betweenthe thumb and forefinger, the spring arm is depressed into the frame,thereby extending the inner member forwardly of the frame so that theblade extends beyond the guard on the frame, such that the blade on theguarded finger scalpel may be used to enlarge the puncture in thepatient's skin, thereby facilitating insertion of the catheter into thepatient, and such that upon release of the thumb and forefinger, thespring arm extends laterally of the frame and the blade is retractedwithin the guard on the frame, and further including means for lockingthe blade in a retracted position of the blade, thereby protecting therespective health care providers in installing the line in the patientand in cleaning up and subsequent disposal of the kit including theguarded finger scalpel therein.
 14. In combination, a guarded fingerscalpel for use by a surgeon in installing a line in a patient,comprising a body having a blade mounted thereon, a guard on the body,resilient means mounted on the body for maintaining the guard in aposition relative to the blade, wherein the blade is covered, whereinthe surgeon may grasp the resilient means for exposing the blade, suchthat the blade has a first covered position and a second exposedposition, and locking means maintaining the blade in its coveredposition, the locking means being independently mounted on the body.